Aircraft: AIRBUS INDUSTRIE UNDIFFERENTIATED OR OTHER MODEL
Phase of flight: Cruise
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

[We were] operating at night VMC cruise flight at FL300. We noticed that the nose wheel landing gear down indication was illuminated while using the Number 2 landing gear indication system. There was a previous write up in the 5- day maintenance log for this occurring recently while using the Number 1 landing gear indication system. There was no gear door light; vibration; noise; increased fuel flow (higher thrust needed for increased drag) or other secondary indication that the nose gear was in the locked down position. There was also no ECAM (Electronic Centralized Aircraft Monitoring System) warning and the QRH (Quick Reference Handbook) did not provide additional guidance. So we decided that it was just an errant signal maybe caused by the deicing fluid. Several minutes later we had a level 2 (Amber) ECAM for the First Officer's TAT (Total Air Temperature) probe failure and the ECAM directed us to monitor the Number 2 ADC (Air Data Computer). There was no additional indication that the Number 2 ADC failed and all the First Officer's flight displays were nominal. As the Captain was referencing the QRH we both acknowledged an acrid; electrical-burning smell in the cockpit. So at this point we had two off nominal electrical indications followed by an acrid odor in the cockpit. It was not clear to us at the time how these two electrical indications could be related (lack of accurate systems knowledge) and we both agreed that it would be prudent to land at a nearby airport where our Maintenance personnel could work on the jet. At this point the Captain took the airplane and became the pilot flying and I performed duties as the pilot not flying. We declared an emergency and expedited a descent into an airport. The whole evolution from FL300 to landing was close to 15 minutes. Center; Approach; Tower and Ground personnel were all very helpful. Airport emergency personnel found no indications of a fire and our 3 jumpseaters did not smell or see smoke. At no time did we have a visual indication of smoke in the cockpit and the Avionics Bay Smoke warning never illuminated. I did not use the huffer fan since we had already decided that we confirmed a smoke smell. 1. Safety- Were we safe? Yes. We made the best risk decision possible. 2. Standard- For the most part we were standard. The challenge here was time compression and getting the entire checklist done with the correct priority. I did not accurately ID audibly the ILS frequency. We were VMC and I did load the approach up in the FMS and Captain already had raw data set up. I also did not get landing data but used the FMS hook for a target landing speed since we had a very long runway. The 02 mask really challenged communication. The jumpseaters stated that they had a difficult time understanding me. I had the ATC communications but missed some of the 1;000 FT calls which indicated to me a degradation of my situational awareness (SA). 3. Unanswered Questions- When we landed none of the Maintenance personnel could not smell the acrid odor. We were dispatched with only the #2 PAC and I wondered if the acrid smell in flight was more pronounced due to less airflow? Suggestions: 4. Opportunities for Improvement? We can land the Airbus after performing Phase 1's; Red ECAMs and ideally the Landing Checklist. When I started to miss the 1;000 FT calls and failed in my pilot not flying duties I should have stopped the checklist and just backed up the Captain. I felt that my SA was caught up well before entering the terminal environment. Timing is an inherent part of SA. The 1;000 FT calls come a lot quicker at high speeds and high descent rates. We at this carrier have done a good job at training for this type of problem and I have reminded myself that you need to 'reset your clock' when working these type of scenarios. The QRH and MEL do not provide Circuit Breaker location for the First Officer's TAT Heat. I should have looked for a popped CB but got too busy with other flight duties. According to Maintenance; the illumination of the down nose gear indication is a no-go item. That information is not clearly provided to crew members. Maintenance found burnt relay in Avionics Compartment. We revisited nose gear issues the following day. Old plane with several repeat issues. An Airbus widebody Nose Gear down-lock illuminated at cruise along with the First Officer's Total Air Temperature heater failure. Shortly thereafter an acrid electrical odor was detected; so an emergency was declared; the QRH completed and the flight diverted to a nearby airport where Maintenance found burnt Avionics Compartment relays.